29 July 2016

Commentary: 2016 U.S. Championship, Round 4 (Yu - Yip)

This next commentary game is from round 4 of the 2016 US Championship (women's section).  I chose it because of the type of opening, which features an attempt by Black to directly challenge White's English Opening early on by exchanging in the center.  White (Jennifer Yu) makes some interesting decisions and notably lets Black (Carissa Yip) get a bit too much of a central hold, which gives Yip a slight advantage and the initiative.  White however starts to get the initiative back after a classic minority attack on the queenside, undermining Black's center and causing her to play too cautiously (see move 19).  Play then revolves around Black's weak c-pawn on the half-open file, which eventually is liquidated, but only after other weaknesses are created that give White a decisive queen move (36. Qf4!) that is an excellent illustration of the power of the queen to do multiple tasks at once.
[Event "ch-USA w 2016"] [Site "Saint Louis USA"] [Date "2016.04.17"] [Round "4.2"] [White "Yu, Jennifer R"] [Black "Yip, Carissa"] [Result "1-0"] [ECO "A16"] [WhiteElo "2157"] [BlackElo "2164"] [Annotator "ChessAdmin/Komodo 9"] [PlyCount "77"] [EventDate "2016.04.14"] 1. c4 Nf6 2. Nc3 d5 3. cxd5 Nxd5 4. g3 {by far the top choice in the database. White goes for immediate piece pressure in the center using the long diagonal.} (4. Nf3 {is the second most popular choice in the database. White avoids committing to the early fianchetto.}) 4... g6 5. Bg2 Nb6 6. Nf3 {in contrast with the move 4 variation, White has chased away the Nd5 before her own knight comes out.} Bg7 7. O-O {retaining maximum flexibility for as long as possible.} Nc6 8. d3 {White cannot reasonably play d4 here, due to Black's piece pressure on the center, but this more modest pawn advance releases the c1 bishop and asserts control over c4 and e4.} O-O 9. Rb1 {an interesting choice by White. Instead of playing a natural bishop developing move, for example Be3 or Bd2, as a follow-up to the previous move, she prefers to initiate queenside action immediately.} Bf5 {a somewhat puzzling square for the bishop, since it's left potentially exposed to harassment by a knight or by an eventual e4 or g4 push, should circumstances favor that. It is in a position to prevent Ne4, however, as a minor piece exchange on e4 would then give Black a 3-2 pawn majority on the queenside.} 10. h3 {this appears to be aimed at nullifying a potential future Q+B battery on the c8-h3 diagonal, after which White plays Kh2 to defend h3. White by this maneuver ensures that she keeps the Bg2 on the board rather than having Black try to exchange it.} (10. Be3 {alternatively would simply ignore Black's idea of exchanging the bishop, in favor of development. Play could continue} Qd7 11. Qd2 Bh3 12. Bh6 Bxg2 13. Kxg2 {and now White will be able to likewise exchange Black's bishop on the long diagonal, which is at least as valuable as its White counterpart.}) 10... e5 11. b4 {White presses ahead with her queenside expansion plan.} Nd4 12. Nxd4 $6 {this unnecessarily gives Black a strongly-supported central pawn, without sufficient compensation elsewhere in the position.} (12. Nd2 $5 $11 {looks a little passive, but it unleashes the Bg2 and keeps White's options open.}) 12... exd4 13. Ne4 { now White's knight lands on a nice central square, but it may have been of more use on c3, hitting b5 and d5.} Nd5 {Black now has a nicely centralized knight of her own.} 14. Bd2 {by this point there are no real alternative squares for developing the bishop.} c6 15. b5 {an easy move to play for White, since her main idea, starting with the 9th move, has been to push the b-pawn into Black's camp. This is a standard minority attack idea, seeking to undermine support for Black's center.} Qe7 {a safe-looking choice, although White's next move is also obvious and will help give her targets on the queenside.} (15... cxb5 16. Rxb5 {and White will have dynamic play on the queenside, although Black's strengths in the center balance this, along with the long-term 2-1 majority on the queenside.}) 16. bxc6 bxc6 17. Qc2 { pressuring the backwards c-pawn on the half-open file is now an obvious strategy for White.} Rac8 18. Rb3 {with the idea of dominating the open b-file. } (18. Qc5 $5 Qxc5 19. Nxc5 {would be a nice-looking positional gain for White, occupying c5 with a knight and opening up the long diagonal.}) 18... c5 { Black correctly looks to advance and then hopefully liquidate the c-pawn, which otherwise will be a long-term weakness.} 19. Rfb1 {consistent, but it gives Black the opportunity to resolve the situation with the c-pawn.} (19. Rc1 $6 {would fail to prevent the advance of the c-pawn, which tactically still works:} c4 20. dxc4 Nc3 21. Bxc3 dxc3 $17 {and White is cut off from protecting the c4 pawn, which Black will soon be able to take and thereby restore the material balance, while also having control over the center and a menacing passed c-pawn.}) 19... Nb6 {this appears to be a turning point in terms of the initiative. Instead of pressing forward, which is tactically possible, Black retreats and then focuses her attention elsewhere.} (19... c4 { and now play is similar to the above variation:} 20. dxc4 ({inserting} 20. Rb7 Qa3 {may be an improved version of the idea for White}) 20... Nc3 21. Bxc3 dxc3 $15) 20. Rb5 {adding sideways pressure against the c-pawn.} Rfe8 21. Bg5 { White is now the one making threats and forcing Black to play reactively.} (21. Rxc5 $2 Bxe4 $19) (21. Nxc5 $6 {the pin against the Qc2 will prove awkward after} Be5 $15 {and now Black threatens simply ...Bd6, also with ideas of possibly sacrificing on g3 in the future.}) 21... f6 $2 {a very committal move that is also unnecessary; there are several reasonable queen moves. Blocking the Bg7 effectively takes away a key piece from Black's game. Although Yip then moves to undo the block, the whole process leaves her more vulnerable and White well-positioned to exploit this.} 22. Bf4 Bxe4 23. Bxe4 f5 24. Bf3 { now it's obvious that White can support an h-pawn advance with her bishops.} Be5 {Black continues to attempt to exchange her way out of her difficulties.} 25. Bxe5 Qxe5 {it's interesting to see that the minor piece exchanges have had their desired effect on the kingside, but look at the remaining pieces. White's light-square bishop is huge, while the black knight is mostly ineffective. White's rooks are also very active and the c-pawn's weakness is magnified.} 26. Rc1 Nd7 27. Qc4+ {White's light-square dominance is well illustrated by this sequence.} Kh8 28. Rb7 Qd6 29. Rxa7 $18 Ne5 {still trying to exchange her way out of trouble, except now she is material down.} 30. Qd5 { a safe approach to handling the position.} (30. Qb5 {is the engine's suggestion, but it involves giving Black some more risky-looking activity, for example} Nxf3+ 31. exf3 {and Black has the e-file to work with and some potential kingside counterplay, although it does not work out in calculation, largely because the c-pawn is too vulnerable to capture.} Qc6 32. a4 $18) 30... Nxf3+ 31. Qxf3 {White's advantage is solid - a passed a-pawn and no real weaknesses, while Black still has the backwards c-pawn - and Black can do little about it.} Qb6 32. Rb7 Qe6 {targeting the one slightly weak point (e2) in White's position and supporting a c-pawn advance...which, however, will be problematic.} 33. Rc2 c4 $2 {this advance comes far too late now and out of desperation.} (33... Qc6 $18) 34. dxc4 {the simplest approach, just take the pawn.} Rxc4 35. Rxc4 Qxc4 {optically it looks like the position is not terribly worse for Black, with the weak c-pawn now gone, but now her exposed king position can be exploited by White's queen.} 36. Qf4 $1 {an excellent example of a decisive queen move that does multiple things. Useful ones include covering c1, getting on the open b8-f4 diagonal and pressuring the d-pawn. However, the most important threat is now to Black's h-pawn, which cannot be adequately defended from the Q+R combination.} Rxe2 {Black desperately tries to distract White, but to no avail.} 37. Qb8+ Qg8 38. Qd6 { with an unstoppable threat on the long al-h8 diagonal.} Re1+ 39. Kh2 1-0

19 July 2016

Publishing chess games online in 2016

It's time again to look at options for publishing chess games online, as the post Publishing Chess Games in 2013 (updated) is still helpful but now significantly behind the latest tools, especially after ChessBase made a recent huge update to its replayer.

My criteria for using an online publishing tool haven't changed.  Here are what I consider to be necessary features:
  • Display full annotations (symbols and text)
  • Variations contained in annotations are displayed on the board
  • Board and annotations must be visible together (the board cannot scroll off the page)
  • Board should be flippable (White or Black can be displayed at the bottom)
  • Can use either mouse or arrow keys to go through the moves
  • Can publish a full game as part of a self-contained blog post 
I'll again use the first annotated game published here (Annotated Game #1, a simul encounter that I drew against GM Walter Browne), as the sample for four major common online publishing tools for comparison.  I'll put the ChessBase one last, since it's the most advanced and also the most recent.  If readers have a different favorite replayer than one of the listed ones, I'd be interested to see comments as to why, along with the URL.

Technical notes:
  • Many game replayers will need to have some of their functions linked/embedded in your blog's stylesheets (CSS), which can be done relatively simply via copy-and-paste of the app-provided CSS code into your blog's template in the "<head>" section.  For example, in Blogger you can paste text there by selecting the Design - Template - Edit HTML menu options.  
  • IMPORTANT: one common issue to be aware of is that using the https (secure http) protocol with blogs that support it (such as Blogger) often won't allow some game replayers to function, as they link in different ways to external sites to run the necessary code, and you can get a warning message about mixing https and http protocol items.  The only solution sometimes is to view the blog via http or https, whichever is supported by the replayer tool.  For example, the first three publishing methods work fine with http, but ChessBase does not; with https, the first and third tools do not function, but Chess.com and ChessBase do work (see below)
  • It's also worth noting that the replayers will likely not work across all browsers, for example the Aquarium 2015 replay board works fine on my tablet, but not on my Android phone in the mobile browser view; the web version works, but is too tiny to see.
1.  ChessOK Aquarium 2015 - this publishing tool is the one in current use on this site and represents a big improvement over the previous Aquarium iteration (Aquarium 2012); the old format can be seen in the above link to the 2013 post.  It's worth noting that there's now an Aquarium 2016 version in release with a few extra program features, but nothing new for publishing is highlighted.  In terms of the game display, the board is standard size and stays put in the brower window while the text and annotations, which are large-size for good readability, scroll up and down (an innovation that appeared in the previous version of the ChessBase replayer).  Documentation of Aquarium's publishing functions is minimal but adequate.  Here's my simple outline of the procedure I use for this blog:
  • Copy your game in PGN format (most database programs have this as a one-button function).
  • Go to the Sandbox tab in Aquarium, clear it, then paste the game.
  • In the menu ribbon, go to Web Export - iBook HTML for Blog, hit OK on the dialog boxes.
  • If it's the first time you're doing this, then you should copy the provided stylesheet links at the top for insertion into your blog's template. Otherwise, just copy only the game code. Paste it into your blog post (using an HTML view of the post).

Browne, Walter - ChessAdmin

Result: 1/2-1/2
Site: Las Vegas
Date: ?
B19: Classical Caro-Kann: 4...Bf5 main line
[...] 1.e4 c6 2.d4 d5 3.¤c3 dxe4 4.¤xe4 ¥f5 5.¤g3 ¥g6 6.h4 h6 7.¤f3 ¤f6 This sub-variation is relatively rare in practice, with Nd7 being played most often. I evaluate it as just as sound and less famiiliar for most White players, making it good for Black. 8.¤e5 ¥h7 9.¥c4 e6 10.£e2 ¤d5 This last sequence is essentially forced after Ne5, which is White's all-out attacking attempt. 11.¥b3 ¤d7 12.¥d2 £c7
My personal opening book is 12...a5 13.a4 ¤xe5 14.dxe5 £b6 15.O-O-O O-O-O as the a5/a4 moves give the Nd5 an outpost on b4 if needed. In general, the idea is to exchange the e5 knight and castle queenside, with the queen deployed to either b6 or occasionally c7, depending on white's play. In the actual game, this is the point where I did not remember the book continuation, although I did remember the idea behind it.
13.O-O ¤xe5 14.dxe5 O-O-O 15.h5 ¥c5 16.¦ad1 ¦d7 17.¦fe1 ¦hd8 18.¥c1 £b6 This illustrates why the normal move earlier is Qb6 rather than Qc7, that would have saved a tempo on the position. 19.c3 ¤e7 20.¦xd7 ¦xd7 21.¥c4 ¤d5 This rook exchange sequence gains Black the d-file and reduces the number of heavy pieces available for White to attack with. 22.£f3 £d8 Both Fritz and Houdini at this point prefer Qc7, which in words means the queen pressures e5 and also helps cover the 7th rank on defense. While doubling up on the d-file looks good, the points of potential rook invasion are at this point well covered by White. 23.¤e4 ¥xe4 24.£xe4 ¥e7 Not the best. Houdini recommends f5 first, which would prevent a future queen invasion on h7. 25.g3 Prevents any funny business from Black on h4 25...¥c5 26.¢g2 ¤e7 It would be better to anticipate the queenside pawn advance with Bb6 27.b4 ¥b6 28.a4 ¦d1 29.a5 Qe2 is necessary to prevent the tactical shot on f2, which however... 29...¦xe1
I also miss. 29...¥xf2!?30.¢xf2 ¦xc1 31.¦xc1 £d2+ employs a queen fork and highlights the value of the queen on the open file.
30.£xe1²30...¥c7 31.£e4 This allows the black queen to penetrate, thereby fully offsetting white's space advantage and two bishops. 31...£d1 32.¥e3 £xh5 33.f4 ¤d5 Houdini says a6 would have been slightly better, although I thought getting the knight into play was more important at the time. 34.¥xa7 ¤xc3
Here both Fritz and Houdini originally thought that 34...£g4 was better, as the queen stays active near white's king with the possibility of advancing the h-pawn to attack. However, Houdini eventually came around to my way of thinking. Both moves are essentially equal.
35.£d3
35.£h7!?± was Fritz's evaluation, although I wasn't afraid of it at the time, believing my piece activity would compensate. Houdini agrees with me.
35...¤d5 36.b5 £g4 Fritz agrees taking the pawn too early is bad.
Not 36...¥xa5 37.bxc6 bxc6 38.¥xd5 exd5 39.£a6+ ¢d7 40.£xa5 £e2+ 41.¥f2 £e4+ 42.¢h2+⁠−
37.¥xd5 exd5 38.bxc6 ¥xa5??
Unfortunately I didn't remember this and admittedly was a bit flustered by White's apparent attack. Better is 38...£e6 39.cxb7+ ¢xb7 40.¥d4²40...¥xa5
39.cxb7+??
Both Browne and I missed 39.£xd5 and White wins 39...£e2+ 40.¥f2+⁠−
39...¢xb7±40.¥e3 £d7 At this point we have reached a dead-even endgame where neither side can hope to make progress with good play. 41.£d4 ¢c8 42.£c5+ £c7 43.£xd5 ¥b4 (This allows white too much space. Better was 43...£b7 44.£xb7+ ¢xb7) 44.f5 After this move, either Qc2 or Qb7 allows Black to comfortably hold. Something like Kh2 could have been tried to keep the queens on and white's space advantage.
Powered by Aquarium

2. Chess.com's Game Editor is an online tool that is relatively simple to use - link to instructions - but you need to ensure that you are using the old version of the site for publishing if you don't have a Chess.com blog, as the new version won't show all of the necessary functions in the GUI.  It has a clean look and good aesthetics, but it still doesn't display the evaluation symbols (+/-).

    
3. Knight Vision PGN Publisher - this was what I used as my first publishing tool.  It is easily accessible online, had all of the features I wanted and was simple to use and customize, if not the most aesthetically pleasing.  It uses Shockwave Flash (which may be an issue) and was last updated in 2013, but is still working.



4.  ChessBase

The biggest change in online game publishing is the recent (early July 2016) unveiling of a completely redone ChessBase replayer.  The previous version was well done aesthetically, in my opinion, but lacked a "flip the board" feature and was not blog-friendly.  The new version has a completely new display method, one that includes a large separate scroll window in the webpage that also allows you to maximize it for a near full-screen experience.  Major other new features are intended to emulate working in a ChessBase software environment, including an ability to drag-and-drop pieces on the board to create your own variations, toggle engine (Fritz) analysis on, annotation tools, and the ability to save or download the game in PGN.  Feature descriptions and instructions can be found at the above link and look easy - just copy the style sheet info into your blog template and then paste PGN data in between an embed code.

[EDIT] After a number of tries, it appears that the ChessBase viewer will not function with an http view of the blog and only works with https.  (There's also a typo in the style sheet code in the linked instructions, if you just paste it in it will cause an error message in Blogger due to a missing "/" or "</link>" at the end of the first HTML code line).  You can see the https blog post view in this link, which correctly displays the ChessBase viewer.


[Event "Simul"] [Site "Las Vegas"] [Date "????.??.??"] [Round "?"] [White "Browne, Walter"] [Black "ChessAdmin"] [Result "1/2-1/2"] [ECO "B19"] [Annotator "ChessAdmin/Fritz/Houdini"] [PlyCount "87"] [EventDate "2006.??.??"] {B19: Classical Caro-Kann: 4...Bf5 main line} 1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 Nf6 {This sub-variation is relatively rare in practice, with Nd7 being played most often. I evaluate it as just as sound and less famiiliar for most White players, making it good for Black.} 8. Ne5 Bh7 9. Bc4 e6 10. Qe2 Nd5 {This last sequence is essentially forced after Ne5, which is White's all-out attacking attempt.} 11. Bb3 Nd7 12. Bd2 Qc7 $146 ({ My personal opening book is} 12... a5 13. a4 Nxe5 14. dxe5 Qb6 15. O-O-O O-O-O {as the a5/a4 moves give the Nd5 an outpost on b4 if needed. In general, the idea is to exchange the e5 knight and castle queenside, with the queen deployed to either b6 or occasionally c7, depending on white's play. In the actual game, this is the point where I did not remember the book continuation, although I did remember the idea behind it.}) 13. O-O Nxe5 14. dxe5 O-O-O 15. h5 Bc5 16. Rad1 Rd7 17. Rfe1 Rhd8 18. Bc1 Qb6 {This illustrates why the normal move earlier is Qb6 rather than Qc7, that would have saved a tempo on the position.} 19. c3 Ne7 20. Rxd7 Rxd7 21. Bc4 Nd5 {This rook exchange sequence gains Black the d-file and reduces the number of heavy pieces available for White to attack with.} 22. Qf3 Qd8 {Both Fritz and Houdini at this point prefer Qc7, which in words means the queen pressures e5 and also helps cover the 7th rank on defense. While doubling up on the d-file looks good, the points of potential rook invasion are at this point well covered by White.} 23. Ne4 Bxe4 24. Qxe4 Be7 {Not the best. Houdini recommends f5 first, which would prevent a future queen invasion on h7.} 25. g3 {Prevents any funny business from Black on h4} Bc5 26. Kg2 Ne7 {It would be better to anticipate the queenside pawn advance with Bb6} 27. b4 Bb6 28. a4 Rd1 29. a5 {Qe2 is necessary to prevent the tactical shot on f2, which however...} Rxe1 ({I also miss.} 29... Bxf2 $5 30. Kxf2 Rxc1 31. Rxc1 Qd2+ {employs a queen fork and highlights the value of the queen on the open file.}) 30. Qxe1 $14 Bc7 31. Qe4 {This allows the black queen to penetrate, thereby fully offsetting white's space advantage and two bishops.} Qd1 $11 32. Be3 Qxh5 33. f4 Nd5 {Houdini says a6 would have been slightly better, although I thought getting the knight into play was more important at the time.} 34. Bxa7 Nxc3 ({Here both Fritz and Houdini originally thought that} 34... Qg4 {was better, as the queen stays active near white's king with the possibility of advancing the h-pawn to attack. However, Houdini eventually came around to my way of thinking. Both moves are essentially equal.}) 35. Qd3 (35. Qh7 $142 $5 $16 {was Fritz's evaluation, although I wasn't afraid of it at the time, believing my piece activity would compensate. Houdini agrees with me.}) 35... Nd5 $11 36. b5 Qg4 { Fritz agrees taking the pawn too early is bad.} ({Not} 36... Bxa5 37. bxc6 bxc6 38. Bxd5 exd5 39. Qa6+ Kd7 40. Qxa5 Qe2+ 41. Bf2 Qe4+ 42. Kh2 $18) 37. Bxd5 exd5 38. bxc6 Bxa5 $4 ({Unfortunately I didn't remember this and admittedly was a bit flustered by White's apparent attack. Better is} 38... Qe6 39. cxb7+ Kxb7 40. Bd4 $14 Bxa5) 39. cxb7+ $4 ({Both Browne and I missed} 39. Qxd5 $142 { and White wins} Qe2+ 40. Bf2 $18) 39... Kxb7 $16 40. Be3 Qd7 $11 {At this point we have reached a dead-even endgame where neither side can hope to make progress with good play.} 41. Qd4 Kc8 42. Qc5+ Qc7 43. Qxd5 Bb4 ({This allows white too much space. Better was} 43... Qb7 44. Qxb7+ Kxb7) 44. f5 {After this move, either Qc2 or Qb7 allows Black to comfortably hold. Something like Kh2 could have been tried to keep the queens on and white's space advantage.} 1/2-1/2

10 July 2016

Commentary: 2016 U.S. Championship, Round 1 (Nakamura - Lenderman)

I'm back to analyzing a select series of commentary games from the April 2016 U.S. Championships.  From major events I try to pull games of particular interest, either due to their openings or particular features that appear, for commentary work.  I find that this complements analyzing your own games well, since it provides a much cleaner framework (typically GM-class games) for showing typical plans and how they can be executed.

Reviewing top-level games also reminds us how nobody is perfect and we can all get into problem situations, as GM Lenderman does in the below first-round game against GM Hikaru Nakamura, the eventual champion.  I selected the game (highlighted in this ChessBase news article) because it shows a gambit and fianchetto approach against the Semi-Slav, which is my own preferred method of combating it.  In terms of thematic material, the game very much highlights the classic ideas behind exploiting a lead in development, including grabbing space and opening lines for your pieces.  Some key tactical themes also include the problem with hanging pieces, various pins, and defending pieces (in this case, a couple of key pawns for White) tactically while advancing your plan.

[Event "ch-USA 2016"] [Site "Saint Louis USA"] [Date "2016.04.14"] [Round "1"] [White "Nakamura, Hikaru"] [Black "Lenderman, Alexsandr"] [Result "1-0"] [ECO "E04"] [WhiteElo "2787"] [BlackElo "2618"] [Annotator "ChessAdmin/Komodo 9"] [PlyCount "75"] [EventDate "2016.04.13"] 1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Nc3 c6 {the Semi-Slav} 5. g3 {here White goes with a kingside fianchetto approach, typical of a Catalan-style opening. I also prefer to play this way vs. a Semi-Slav style setup, although I'm not a 1. d4 player. This is also in effect a gambit approach, since Black can opt (as in the game) to take and try and hold the c-pawn.} dxc4 (5... Nbd7 {is most often played here and often signals a desire to keep the central structure and play for the e5-e4 break eventually.}) 6. Bg2 b5 7. O-O Bb7 8. b3 {this is the only game in the database with this move; Nakamura is often not afraid to be experimental in the opening. Most often played is Ne5, focused on targeting the c6 pawn, but White scores below par (45 percent).} ({Here's one game with a similar approach, although Nakamura accelerates the idea by a tempo.} 8. Ne5 Qb6 9. b3 cxb3 10. Qxb3 Be7 11. Rd1 O-O 12. e4 a5 13. Be3 a4 14. Qc2 Qa5 15. a3 Na6 16. Nd3 Rac8 17. Rdb1 Ba8 18. Bd2 Qd8 19. e5 Nd5 20. Ne4 Nb6 21. Ndc5 Nxc5 22. dxc5 Nd7 23. Bf4 g5 24. Be3 Nxe5 25. Rd1 Qc7 26. Nxg5 Ng6 27. h4 Rfd8 28. h5 Nf8 29. Qc3 Rxd1+ 30. Rxd1 Rd8 31. Re1 e5 32. f4 Bf6 33. Ne4 Bg7 34. f5 Qe7 35. h6 Bh8 36. Bg5 f6 37. Be3 Qf7 38. Nd6 Qa7 39. Qc2 {1-0 (39) Hovhannisyan,M (2515)-Hautot,S (2360) Charleroi 2015}) 8... cxb3 {here I wonder if this move wasn't in part driven by psychological factors, as a relatively safe-looking approach.} (8... b4 {looks the most testing, as Komodo assesses.} 9. Na4 c3 10. a3 a5 11. Ne5 Nbd7 {and Black looks fine, with the c6 pawn tactially protected, for example:} 12. Nxc6 $2 Qc7 13. Ne5 Bxg2 14. Kxg2 Nxe5 15. dxe5 Qxe5 $17) 9. Qxb3 {now the game has transposed back to the database, with a very small but very favorable record for White (75 percent).} Be7 10. Ne5 a6 11. Rd1 O-O 12. Ne4 {an effective move for the piece. The knight on c3 is not contributing materially to White's game, so Nakamura prepares to transfer it. Bg5 has been previously played here, with success, but Nakamura prefers to leave that square open for the Ne4 to move to.} Qc7 (12... Nbd7 $5 {would directly challenge the Ne5.}) 13. Ng5 {showing the value of targeting the traditionally weak f7 pawn, even when it is still protected by the Rf8, when the square e6 is also under attack. This is also a typical tactical theme in the Caro-Kann, where Black has to watch for sacrifices involving attacks on f7/e6.} a5 (13... h6 $6 14. Ngxf7 Rxf7 15. Qxe6 {and Black has problems.}) 14. Bh3 {we are still far from the point where forced variations will get White anything. Nakamura bides his time and is content to engage in a maneuvering battle. Here e6 is targeted yet again, ignoring the (overprotected) c6 pawn.} a4 15. Qc2 {at this point the engine shows a slight plus for White. Black cannot have been too happy with the opening, as evident after the next move, which brings all the queenside pieces back to their original squares.} Bc8 {a logical and correct move to protect e6, but it still must have been annoying to have to do. Black has little dynamic play available and his approach must be to hold onto the extra pawn and hope White's initiative proves fruitless. Normally Black would also try to look for a way to give back the material to fully equalize, for example in the move 17 variation below.} 16. Bf4 Qd8 {the queen has to move off the b8-h2 diagonal because of the threat of discovered attack.} 17. Ng4 { containing the obvious threat of exchanging the Nf6 and playing Qxh7 mate.} g6 {this weakens the king position and helps make Black's edge more concrete.} ( 17... Nbd7 $5 18. Be5 h6 19. Nxf6+ Nxf6 20. Bxf6 hxg5 21. Bxe7 Qxe7 22. Qxc6 Bd7 {and the engine shows equality, but the position looks much easier for White to play.}) 18. Nxf6+ Bxf6 19. Ne4 Bg7 (19... Be7 $5 {helping cover d6 may have been better, in light of White's 21st move, although it's understandable wanting to fill the kingside holes.}) 20. Bg2 $16 {the long diagonal becomes more important to occupy again, now that the sac threat against e6 is over. The engine's significant plus for White is easy to visualize here, given White's advantage in development (five pieces to one) and space.} Qb6 21. Bd6 {a good example of how to exploit better developed pieces and seize yet more space.} Re8 22. Rac1 Qd8 {moving back to the original square. Black has to be frustrated by this point.} 23. Bc5 Ba6 24. Bb4 Qc7 {playing defensively around the c6-pawn. But now Nakamura illustrates the principle of the benefits of opening the position when ahead in development, as well as highlighting the tactical danger of placing pieces (the Qc7) onto undefended squares.} (24... Bb7) 25. d5 $1 $18 {this pawn lever effectively breaks open the position for White's pieces in the center.} exd5 26. Nd6 { the point being a double attack (with the knight on the Re8 and the Bg2 on the d5 pawn; the c6 pawn is pinned against the Qc7 and no longer protects d5).} Qd7 {hoping that giving back material (i.e. the Re8) will exhaust White's initiative.} (26... Rf8 27. Bxd5 Qe7 {moving out of the pin still leaves White with a big advantage and Black with little he can do about it, for example} 28. Bg2 Qe5 29. Rd2 Bc8 30. Bc5 Bd7 31. Nxb5 Rc8 32. Nd6 $18) 27. Nxe8 Qxe8 { there is now less material on the board and the balance is roughly even, but White still has the far-better developed pieces, so continues to find success by opening lines in the center.} 28. e4 d4 29. e5 {and the pawn is tactically protected, as either the bishop or queen taking on e5 would be followed up by Re1, losing Black material.} h5 {this gives Black an escape square on h7, but there's little else he can do at this point.} 30. f4 {the pawn on d4 is now doomed and trying to keep the material balance doesn't help Black.} f6 31. Rxd4 fxe5 32. fxe5 Bc8 (32... Bxe5 $2 {the pawn is still tactically protected} 33. Re4 $18) 33. Rcd1 {a simple yet powerful follow-up.} Bd7 {Black blocks the penetration of a rook on d8, but now White has too many other threats, including on g6.} 34. Rd6 Qxe5 35. Qxg6 Qf5 36. Bc3 {a beautiful move which puts maximum pressure on Black. Now the Bg7 is doomed.} (36. Rf1 {would be a less incisive but still practical way of winning.} Qxg6 37. Rxg6 $18) 36... Qf7 37. Rf1 Qxg6 38. Rxg6 {and after the bishop goes, White will have a mate in 5.} 1-0